Identifying junctions/branches. Final configurations of cells, like those shown in Figs. REF  and REF , are re-plotted with elongated black markers on cell positions along the direction of the dipole axis. This gives us networks like those shown in Fig. REF . These images are imported into imageJ [1]}, Gaussian blurred, intensity thresholded, binarized, and skeletonized. By then using the "Analyze Skeleton" plugin in ImageJ, we obtain skeleton information including the full branch length distribution and junction counts.
